The World Cup is now in full swing, and millions of families around the world are getting together to watch soccer games, and to root for their favorite team.

For some families, supporting a specific team is mandatory, and it's passed down through the generations, like DNA. Some fans root for their home team, based on where they live or have lived at one point, while others choose a team based on other criteria.

Do you and your family all root for the same sports teams? Let us know in the poll below!

So many of our families have branches living in diverse countries, so our question today reflects that reality.

Which national teams - of our varied heritages - are those we roots for at major events, such as the Olympics? And, of course, why do we cheer so loudly for our national teams during the Olympics?

Experts at the University of Texas, Dallas offer several explanations of how we define ourselves via membership in a larger group, sometimes called “collective identity.”

UTD Researcher Dr. Karen Huxtable-Jester says this tendency is stronger in men than women, but everyone seems to enjoy cheering for their national team. She teaches psychology in The University of Texas at Dallas’ School of Behavioral and Brain Sciences.

Another impetus for this is that people like to associate with successful people. Researchers call this BIRG (basking in reflected glory).